Urinary excretion by nonionic diffusion

Abstract

Certain aspects of excretion of some basic amines by a pH-dependent diffusion mechanism have been studied. Dimethylaminoisocamphane, aminoisocamphane, and a new hypotensive agent, pentamethylpiperidine, have been shown to have pH-dependent clearances which are high in acid urine and low in an alkaline urine. If these amines are excreted by a diffusion mechanism their clearances should be independent of the plasma amine level. If pH is kept constant the amine clearance should be increased by an osmotic diuresis. Experimental results conform to these predictions. Taken together, the results make it unlikely that the excretion of these basic amines is carried out by a pH-sensitive transport system. Results are presented which suggest that the amine carried in the red cells may be cleared by the kidney.